The Federal Reserve left its benchmark interest rate unchanged on Wednesday, but it issued an upbeat assessment of economic conditions that suggested a growing chance that it would increase rates later this year.The Fed, in a statement after a two-day meeting of its policy-making committee, said that the economy had overcome wobbles this year and that job creation had increased with moderate economic growth.Importantly, the central bank added that it saw fewer clouds on the horizon as the United States entered the eighth year of an economic expansion.“Near-term risks to the economic outlook have diminished,” the statement said, though it added that the Fed remained wary about the weakness of inflation and about “global economic and financial developments.”Janet L. Yellen, the Fed’s chairwoman, has won broad support among Fed officials for a patient approach to raising rates.